Complete Freund's adjuvant, a water in oil emulsion, is the most common adjuvant used to stimulate antibody response in rabbits. Its use is often associated with undesirable side effects at the inoculation site, such as inflammatory lesions, tissue necrosis, and even local sloughing. The RIBI Adjuvant System, an oil in water emulsion, is the most frequently used alternative to complete Freund's adjuvant. RIBI utilizes bacterial cell walls and byproducts which have been purified to eliminate the toxicity and allergenicity associated with the intact tubercle bacillus contained in complete Freund's adjuvant. This study will examine intradermal, subcutaneous, intramuscular and intraperitoneal routes of inoculation in the rabbit, comparing the two adjuvants at varying dosage levels. Rabbits will be clinically evaluated for pain and distress, and gross and histopathologic collections will be made and examined at 1, 2, 3, or 4 weeks postinoculation. Rabbits scheduled for sacrifice on fertility studies will be used. Collaborations with investigators in other laboratories will be initiated to evaluate and compare antibody response to antigens under the varying experimental conditions. We hope to obtain a profile of the method(s) which result in maximum antibody response with minimum undesirable tissue reactions, benefitting the experimental animal and improving the scientific result.